Metal stitching



June 17, 1958 A. L. AMEND METAL swrrcnmc 4 Sheets-Sheet 1 Filed' Nov. 23, 1955 INVENTOR ArZ%rL, Amend BY (Wm ATTORNEYS.

June 17, 1958v A. L. AMEND 8 2,838,968

METAL swrrcnmc 4 Sheets-Sheet 2 Filed Nov. 23, 1955 ATTORNEYS June 17, 195 8 A. L. AMEND METAL S'TITCHING 4 Sheets-Shet 3 Filed novjzs, 195s 1 June 17, 1958 A. L. AMEND 2,

I METAL STITCHING Filed Nov. 23, 1955 4 Sheets-Sheet 4 INVENTOR Affwr Z Ame/ad:

ATTORNEYS United States Patent METAL STITCHING Arthur L. Amend, Oakford, Pa.

Application November 23, 1955, Serial No. 548,642

1 Claim. (Cl. 7,8-1)

The present invention relates to stitching of metal sheet.

A purpose of the invention is to stitch together metal sheets in a manner which is more reliable and more resistant to separation and which more securely anchors the stitch in place.

A further purpose is to stake the stitch in the stitch recess by deforming the sheets adjacent the stitch and desirably lower the stitch itself.

"A further purpose is to project a stitch in the stitch recess and stake the stitch of continuousforward motion in the same direction.

A further purpose is to punch the stitch recess by one punching means and then move that punching means laterally to receive another punching and staking device which has previously formed a stitch and now projects the stitch into the stitch recess and stakes the stitch.

A further purpose is to prevent the stitch forming punch in one position from advancing far enough to damage one of the sheets. I v

Further purposes appear in the specification and in the claims. W

In the drawings I have chosen to illustrate oneonly of the numerous embodiments in which the invention may appear, selecting the forms shown from the standpoint of convenience in illustration, satisfactory operation, and clear demonstration of the principles involved.

Figure 1 is a top plan view partly broken away showing the stitching machine of the invention.

Figure 2 is a front elevation of the device of Figure 1 partly in axial section.-

Figure 3 is a side elevation of the stitching machine of the invention, partly in axial section on the line 33 of Figure 2.

Figure 4 is a fragmentary enlarged axial section show ing both punches in the punching position taken on the line 44 of Figure 1.

Figure 5 is a section on the line 5--5 of Figure 4.

Figure 6 is a section on the line 6-6 of Figure 4.

Figure 7 is a section on the line 77 of Figure 4.

Figure 8 is a section on the line 88 of Figure 4.

Figure 9 is an enlarged fragment of Figure 4 partly in section.

Figure 10 is a front elevation partly in axial section showing the punches shifting to the staking position.

Figure 11 is an enlarged fragment of Figure 10 showing the position of staking.

' Figure 12 is an enlarged fragment of Figure 11 showing staking.

Figure 12a is a top plan view of the stitch.

Describing in illustration but not in limitation and referring to the drawings:

In many machining operations and as a means of uniting metal sheets'together for other purposes, it is desirableto be able to stitch metal sheets. One example is for feedingsheets to an automatic punch press operation. v p p p 7 r -When reference is made herein to sheets it is intended to include plates, of any suitable metal such as iron,

2,838,968 Patented June 17, 1958 steel, aluminum, base alloy, copper base alloy, magnesium base alloy, or the like.

Difficulty has been encountered in prior art stitching of metallic sheet due to the tendency of the stitch to become dislodged. Also certain prior art stitching techniques have been tedious in application. The present invention provides a stitching machine which operates very conveniently, but anchors the stitch so firmly that it is not likely to be dislodged. Accordingly, it is possible by the invention to produce an unusually strong stitch staked in place. Also the invention permits punching of the stitch recess and also forming of the stitch, inserting and staking of the stitch in the same machine without moving the work. t

Considering now the drawings in detail, the stitching machine has a frame consisting of a base 21, uprights 22 at the respective ends and a top 23.

Shafts 24 and 25 abutting end to end and coaxial are journalled in the top structure at 26, 27 and 28 and operated by operating handles 30 at the ends of the respective shafts.

Each of the shafts carries a gear 31 or 32 keyed thereon and the gears mesh with racks 33 or 34 which are on rams guided to reciprocate in the top. The lower ends of the rack arms have T-slots 35 which are adapted toeugage the operating punch elements as later described. The T-slots are arranged to make slidingengagement laterally.

The bottom of the frame provides horizontal ways 36 which guide and support punch assemblies 37 and. 38 which are also guided by a cross-rod 40 passing through the punch assemblies and anchored in the uprights 22'of the frame. The punch assemblies are maintained in spaced relation by a spacer 41 and secured together by The head .47 has a central guide opening 51 which receives a punch body 52 but reciprocably up and down and holding at the lower end a punch 53 which cooperates with a, die 46. The operating end of the punch is suitably of dumbbell shape conforming with the shape of the stitch as later described. The top of the punch body is of T-formation at 54 to engage the T of the ram plunger so that although the punch body can be moved back and forth when in line and it is reciprocated by the rack plunger. The bottom of the head is provided with a hold-down plate 55 which conforms to the shape of the punch.

Punch unit 38 has a die holder 56 at the bottom which has a central recess 57 which receives a staking die 58. The recess is in line with an access opening 60 .to assist in removal of the die, this opening in one position cooperating with an opening 61 in the base and in another position cooperating with an opening 62 in the base.

A punch head 63 is secured at the front tothe anvil portion 56, leaving a front opening slot 64 for the sheets being joined, this slot being horizontally in line with the slot 50 in the other die unit. A'vertical guide opening 65 is provided in the head and a ram 66 reciprocates in the guide opening and has a T-head 67 which cooperatively engages in either'of the T-slots 35 so that it can be reciprocated by either'of the rack plungers. 'The.

ram 66 mounts a punch 68, the punch being suitably shouldered at 70 and having a lower shearing end of generally dumbbell shape adapted to cooperate with the stitch recess as later explained. Below the ram is a washer-like upper staking die 71 which has an opening of the same general contour as the shearing operation of the punch and acts as a die to cooperate with the punch. The die 71 has a transverse slot 72 in line with a lateral slot 73 to receive the material 74 from which the stitch is to be formed.

The punch head also has a transverse slot 75 above the die to receive a fork-like stop 76 in the left hand position of Figure 2 which limits downward motion of the punch. The stop 76 is secured at 77 from one of the uprights 22. The slot 64 is also high enough to receive in addition to the stop and limiter, a stop 78 which prevents the upper staking die from engaging the stop in the left hand position of Figure 2.

The bottom die 58 has ridges 80 protruding upwardly in lie with spaced positions at opposite ends of the punched opening and the upper die '71 has downwardly directed staking projections which are suitably disposed at opposite ends of the punched opening and slightly displacedon either side of the staking projections 81 of the lower die.

In order to permit shearing off excess of stock from which the punching is made, the punch housing is slotted at 82 beyond the die 71 and cooperating shear blades 83 on the ram and 84 on the punch head 63 are provided which shear off stock protruding beyond the housing. The shear blade 83 is supported on a plunger 83' guided by a T-slot 83 in the adjoining punch unit.

The opening in the lower portion of the die 71 provides substantially straight or slightly diverging portion 85 as best seen in Figure 9, which holds the stitch 86 after it has been punched out of the strip 74 from which the stitch is formed.

Suitable holding and guiding means are provided for the plates being stitched, desirably including bosses 87 on the frame which adjustably position rods 88 which support and stock stop 90 at the rear of the machine assuring that the plates are lined up as intended. The plates suitably rest on supports 91 on the frame and the rods 88 may be provided with secondary limiters 92 which are suitably adjustable thereon as by set screws.

In operation of the mechanism of the invention, with the punch units in the extreme left-hand position as shown in Figures 1, 2 and 4, two plates or sheets 93 and 94 to be stitched together are interposed, and suitably adjusted against the stop 90 and rested on the supporting portions 91. The seam between the plates is lined up at 95 under the middle of the punch 53.

Stock 74 from which the stitch is to be formed, suitably of lighter gage than the sheets or plates to be stitched together, is inserted under the die 68. Both dies in this position are raised or retracted.

Using the operating handles or other operating means,

the operator punches out a suitably dumbbell formation having the bulbous ends on opposite sides of the seam, and knocking out punchings 96 as shown at the right of Figure 4. The operator then retracts the punch 53.

The operator also brings down the punch 68 into the die 71, but the shoulder 70 on the punch engages the fork ends of the stop 77 and limits the motion of the punch 68, merely punching out a stitch 86 and forcing it into gripping engagement with the slightly diverging walls 85 of the die where the stitch is held for transportation with the punch unit. As is common in punching operations, the stitch has a slightly depressed side edge 97 which is smaller at the top and wider at the bottom, and this assists in engagement in the slightly downwardly diverging walls 85 of the die.

It will be noted that the punch 68 is not permitted to move down far enough to mark or damage the work plate or sheet 94 which is immediately below it and is not permitted to stake this sheet, due to the protection of the stop 78 'which extends across beneath the upper staking die and beneath the punch 68.

The operator then retracts the punch 68 leaving the stitch in the position shown in Figure 9.

The punch units are then slid across the machine from the position of Figures 1, 2 and 4 to the position of Figure 10, by pulling on the handle 43. While this is taking place the plates to be stitched remain in the same position and the die units simply slide with respect to the plates or sheets.

With the die units now in the position of Figure 10, it will be noted that the stops 76 and 78 are no longer operative and the punch 63 as well as the upper die '71 are free to move down.

On operation of the appropriate lever, the gear and rack having established contact with the head 67 forces the punch 68 down and this ejects the stitch 86 from its position supported by the walls 85 of the die into the bottom of the punch opening in the plates, with appropriate engagements in the bulbous portions of the stitch across the seam.

Further forward motion of the shoulder 70 of the punch 68 brings die 71 down against the plates, so that the staking projections become operative 'while staking projections 81 on the lower die cooperate, and the metal of the plates or sheets being joined is staked or deformed at 98 by the upper staking projections and the metal of the stitch and of the plates or sheets being joined is deformed at 100 by the lower staking projections. The staking at 98 fills in the space which would otherwise exist due to "the narrowness of the stitch at the top on account of its slight taper. The effect is to grip the stitch firmly in the plates or sheets with the neck 101 of the stitch bridging the seam and the dumbbell portions 182 in the corresponding recesses on opposite sides of the seam, and deformed metal holding the stitch against displacement upwardly or downwardly.

The gripping of the stitch without protruding beyond the plates or sheets is aided by the fact that the stitch is of lighter gage.

The punch 68 is now retracted and the plates or sheets stitched together can be removed.

Of course as many points of stitching may be utilized as desired and for this purpose the above sequence is repeated, simply moving the plates or sheets to different locations.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claim.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

In a stitching machine, a punch having a contour which provides enlargements at the two ends, a cooperating die having an opening provided with the contour of the punch adapted to shear a stitch when the punch advances, the die having later-a l walls which engage and hold the stitch, forward staking surfaces on the forward face of the die, projections on the punch for engaging .and advancing the die as the punch advances beyond a predetermined position, there being relative movement between the punch and the die before the predetermined position is reached,

and a staking anvil cooperating with the punch and the die.

References Cited in the file of this patent UNITED STATES PATENTS Newcomb June 19, 1956 

